Blood and interstitial fluid sampling device

ABSTRACT

A device and method for lancing a patient, virtually simultaneously producing and collecting a small fluid sample from a body. The device comprises a blood collection system including a lancing needle, drive mechanism, kneading or vibration mechanism, optional suction system, and sample ejection mechanism. The device is preferably sized to be hand-held in one hand and operable with one hand. The device can optionally contain integral testing or analysis component for receiving the sample and providing testing or analysis indication or readout for the user. In one configuration, the lancing needle may be withdrawn very slightly from the point of maximum penetration to create an opening in which blood can pool before being suctioned through to device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/562,496, filed Nov. 22, 2006 (Attorney Docket No. 007404-000791 21214US3), which is a continuation of U.S. patent application Ser. No.10/835,094, filed Apr. 29, 2004 (Attorney Docket No. 007404-000622 21214US2), which is a continuation of U.S. patent application Ser. No.09/988,799, filed Nov. 20, 2001, now U.S. Pat. No. 6,793,633 (AttorneyDocket No. 007404-000191 21214 US1) which is a continuation of U.S.patent application Ser. No. 09/180,839, filed May 10, 1999, now U.S.Pat. No. 6,332,871 (Attorney Docket No. 007404-000190 21214 US), whichwas a National Stage of International Application No. PCT/US97/08762,filed May 16, 1997 (Attorney Docket No. 007404-000189 21214 WO), whichclaims the benefit of U.S. Provisional Application No. 60/017,133, filedMay 17, 1996 (Attorney Docket No. 007404-00139), which are all herebyincorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to devices and methods for obtainingsamples of blood and other fluids from the body for analysis orprocessing.

BACKGROUND OF THE INVENTION

Many medical procedures in use today require a relatively small sampleof blood, in the range of 5-50 μL. It is more cost effective and lesstraumatic to the patient to obtain such a sample by lancing or piercingthe skin at a selected location, such as the finger, to enable thecollection of 1 or 2 drops of blood, than by using a phlebotomist todraw a tube of venous blood. With the advent of home use tests such asself monitoring of blood glucose, there is a requirement for a simpleprocedure which can be performed in any setting by a person needing totest.

Lancets in conventional use generally have a rigid body and a sterileneedle which protrudes from one end. The lancet may be used to piercethe skin, thereby enabling the collection of a blood sample from theopening created. The blood is transferred to a test device or collectiondevice. Blood is most commonly taken from the fingertips, where thesupply is generally excellent. However, the nerve density in this regioncauses significant pain in many patients. Sampling of alternate site,such as earlobes and limbs, is sometimes practiced to access sites whichare less sensitive. These sites are also less likely to provideexcellent blood samples and make blood transfer directly to test devicesdifficult.

Repeated lancing in limited surface areas (such as fingertips) resultsin callous formation. This leads to increased difficulty in drawingblood and increased pain.

To reduce the anxiety of piercing the skin and the associated pain, manyspring loaded devices have been developed. The following two patents arerepresentative of the devices which were developed in the 1980s for usewith home diagnostic test products.

U.S. Pat. No. 4,503,856, Cornell et al., describes a spring loadedlancet injector. The reusable device interfaces with a disposablelancet. The lancet holder may be latched in a retracted position. Whenthe user contacts a release, a spring causes the lancet to pierce theskin at high speed and then retract. The speed is important to reducethe pain associated with the puncture.

U.S. Pat. No. 4,517,978, Levin et al., describes a blood samplinginstrument. This device, which is also spring loaded, uses a standarddisposable lancet. The design enables easy and accurate positioningagainst a fingertip so the impact site can be readily determined. Afterthe lancet pierces the skin, a bounce back spring retracts the lancet toa safe position within the device.

In institutional settings, it is often desirable to collect the samplefrom the patient and then introduce the sample to a test device in acontrolled fashion. Some blood glucose monitoring systems, for example,require that the blood sample be applied to a test device which is incontact with a test instrument. In such situations, bringing the fingerof a patient directly to the test device poses some risk ofcontamination from blood of a previous patient. With such systems,particularly in hospital settings, it is common to lance a patient,collect a sample in a micropipette via capillary action and then deliverthe sample from the pipette to the test device.

U.S. Pat. No. 4,920,977, Haynes, describes a blood collection assemblywith lancet and microcollection tube. This device incorporates a lancetand collection container in a single device. The lancing and collectingare two separate activities, but the device is a convenient singledisposable unit for situations when sample collection prior to use isdesirable. Similar devices are disclosed in Sarrine, U.S. Pat. No.4,360,016, and O'Brien, U.S. Pat. No. 4,9249,879.

U.S. Pat. Nos. 4,850,973 and 4,858,607, Jordan et al., disclose acombination device which may be alternatively used as a syringe-typeinjection device and a lancing device with disposable solid needlelancet, depending on configuration.

U.S. Pat. No. 5,318,584, Lange et al., describes a blood lancet devicefor withdrawing blood for diagnostic purposes. This invention uses arotary/sliding transmission system to reduce the pain of lancing. Thepuncture depth is easily and precisely adjustable by the user.

Suzuki et al., U.S. Pat. No. 5,368,047, Dombrowski, U.S. Pat. No.4,654,513 and Ishibashi et al., U.S. Pat. No. 5,320,607, all describesuction-type blood samplers. These devices develop suction between thelancing site and the end of the device when the lancet holding mechanismwithdraws after piercing the skin. A flexible gasket around the end ofthe device helps seal the end around the puncture site until adequatesample is drawn from the puncture site or the user pulls back on thedevice.

U.S. Pat. No. 4,637,403, Garcia et al, and U.S. Pat. No. 5,217,480,Haber et al, disclose combination lancing and blood collection deviceswhich use a diaphragm to create a vacuum over the wound site.

International Application Publication Number WO 95/10223, Erickson etal, describes a means of collecting and measuring body fluids. Thissystem uses a disposable lancing and suction device with a spacer memberwhich compresses the skin around the lance/needle.

Single use devices have also been developed for single use tests, i.e.home cholesterol testing, and for institutional use to eliminatecross-patient contamination multi-patient use. Crossman et al, U.S. Pat.No. 4,869,249, and Swierczek, U.S. Pat. No. 5,402,798, also disclosedisposable, single use lancing devices.

Even with the many improvements which have been made, the painassociated with lancing remains a significant issue for many patients.The need for blood sampling and the fear of the associated pain is alsoa major obstacle for the millions of diagnosed diabetic, who do notadequately monitor their blood glucose due to the pain involved.Moreover, lancing to obtain a blood sample for other diagnosticapplications is becoming more commonplace, and a less painful, minimallyinvasive device is needed to enhance those applications and make thosetechnologies more acceptable.

An object of the present invention is to provide a device and a methodfor obtaining a sample of bodily fluid through the skin which isvirtually pain free and minimally invasive.

Another object of this invention is to provide a method which can resultin a sample of either blood or interstitial fluid, depending on thesample site and the penetration depth utilized. While there are nocommercially available devices utilizing interstitial fluid (ISF) atthis time, there are active efforts to establish the correlation ofanalytes, such as glucose, in ISF compared to whole blood. If ISF couldbe readily obtained and correlation is established, ISF may bepreferable as a sample since there is no interference of red blood cellsor hematocrit adjustment required.

Another object of this invention is to provide a method which can draw asmall but adjustable sample, i.e. 3 μL for one test device and 8 μL foranother test device, as appropriate.

Another object of this invention is to provide a method by which thedrawn sample is collected and may be easily presented to a testingdevice, regardless of the location of the sample site on the body. Thisapproach helps with infection control in that multiple patients are notbrought in contact with a single test instrument; only the samplingdevice with a disposable patient-contact portion is brought to the testinstrument. Alternatively, the disposable portion of a test device maybe physically coupled with the sampler so the sample can be broughtdirectly into the test device during sampling. The test device may thenbe read in a test instrument if appropriate or the testing system can beintegrated into the sampler and the test device can provide directresults displayed for the patient.

It is a further object of the invention is to provide a device forminimally invasive sampling comprising a reusable sampler and disposablesample collection.

SUMMARY OF THE INVENTION

In one aspect, the present invention relates to a device which usesmechanical motion to pierce the skin, and a mechanical kneading oroscillation to produce a sample of fluid from the body and may employ aback pressure or vacuum to collect a small fluid sample into the device.More specifically, the present invention comprises a reusable samplingdevice and a disposable piercing/collecting apparatus. The device mayalso employ a back pressure, capillary or vacuum to collect a smallfluid sample into the piercing/collecting apparatus that may later bedischarged to deliver the collected sample to a test device or otherappropriate vessel. The system may alternately be used to deliver thesample to an integral disposable test device, without collecting andseparately dispensing the body fluid sample.

A method aspect of this invention involves piercing of the skin at arapid rate (to minimize pain), with a needle (which minimizes the traumaand pressure-associated pain response which occurs with a traditionallancet). The skin is kept taut during the lancing to allow accurate andrepeatable penetration of the needle into the skin. After piercing theskin, the needle is withdrawn from the wound and the surrounding areakneaded by ultrasonic action, piezoelectric or mechanical oscillation orsqueegee motion to stimulate the blood flow into and from the wound.Additionally heat, electrical potential or friction can be used tostimulate additional flow of the body fluid. This fluid or blood flowcan also be stimulated by ultrasonic vibration of the skin surroundingthe wound. In an alternate embodiment to stimulate blood flow, theneedle remains in the wound for a period of time, with either slowmechanical vibration or rotation of the needle, ultrasonic, orpiezoelectric oscillation of the needle, to keep the wound open forblood to pool. After the area has been stimulated and the blood wells upin the wound, a capillary, syringe or pumping system is used to drawmicroliter samples from the patient. Suction is applied to the needle orthe suction tube through either peristalsis, convection (application ofheat to a capillary tube) or by the piston of a small microsyringe. Thepiston is pulled back into the sampler device with spring action,generating a vacuum in the barrel of the microsyringe and quicklydrawing fluid from the body through the needle or the suction tube intothe barrel to normalize the pressure differential. The piston or suctiondevice then can be reversed to dispense the collected sample. The systemcan also use a capillary tube which is used to draw the sample after ithas been collected on the skin surface. The capillary tube can thendispense the sample to a desired test or analysis device by applyingpressure through the tube or simply contacting the end of the tube andthe sample with a surface or material that has sufficient affinity forthe fluid to pull the sample from the tube.

The above method and system may be used on various parts of the body. Itis particularly appropriate for use on sites other than the fingertips.Although fingertips provide good blood flow, the high density of painreceptors provide for easy access to blood but maximum pain in sampling.The method of this invention actively draws a sample from the body,enabling the use of sampling sites on the body which are inadequate fortraditional lancing. Since the method can also provide a mechanism forthe easy transfer of the sample, the difficulty of bringing the sampleto a test device is eliminated. An important benefit of this system isthat the use of alternate sites on the body reduces the accompanyingpain sensation and encourages more frequent use as needed.

While the method may be readily used to obtain a blood sample in aminimally invasive fashion, a sample of interstitial fluid may similarlybe obtained, generally utilizing a less deep puncture in sites withlower blood flow. This will become more important as tests are developedwhich can utilize ISF samples, which may be preferred compared to blood.

This invention provides a device and method for lancing a patient andvirtually simultaneously producing and collecting the fluid sample,which may be transferred to a test device. A preferred device of thepresent invention comprises a blood collection system including alancing needle, drive mechanism, kneading or vibration mechanism andoptional suction system and sample ejection mechanism. The device ispreferably sized to be hand-held in one hand and operable with one hand.The device can optionally contain integral testing or analysis componentfor receiving the sample and providing testing or analysis indication orreadout for the user.

The lancing needle and firing mechanism designed to create a wound whichwill both provide an adequate sample but which will still close and healquickly. Wound healing is an especially important consideration fordiabetic patients who often have compromised circulatory systems andslow healing processes. The wound must have a geometry which allows fora momentary space in which blood can fill, taking into account theelastic nature of the skin tissues. Careful consideration must be givento these geometries or the dermis will seal around the lancing needletip, precluding the drawing of a sample through the tip. In a preferredembodiment a needle is used in combination with a flexible collar andouter tube to spread the wound so blood can pool. Alternatively amultiple needle lancing device can be used to generate a wound whichdisrupts multiple capillary areas to quickly provide large sample size,but the smaller multiple wounds, can heal more easily.

In an alternate embodiment, the needle/lance is withdrawn from thewound, and the area surrounding the wound is massaged or stimulated toprevent it from closing and to promote the flow of body fluids and orblood to the wound and to the surface of the skin.

Devices according to this invention create a lancing motion which cutsinto the small but plentiful capillaries in the superficial vascularplexus under the epidermis. This vascularized region starts at a depthof 0.3-0.6 mm from the surface of the skin in many accessible areasthroughout the body (forearm, thigh, abdomen, palm). Blood is inplentiful supply in this region of the skin, and healing of small woundsis not problematic. However, bringing a sizable drop of blood to thesurface is more problematic than with a finger stick. A finger stick istypically massaged to increase momentary blood flow. This inventionprovides a system for mechanically massaging a lance site at other bodylocations by several different approaches, including oscillating anannular ring surrounding the wound to pump the blood surrounding thewound into the wound for extraction by a needle or capillary tube oroscillating paddles or other members adjacent the wound to achieve thedesired blood flow. Further, bringing a drop of blood from the skin inother regions of the body, e.g., the thigh, to a small area on a testdevice is very difficult. An alternate embodiment of the presentinvention works with the needle remaining in the wound and the needlebeing mechanically manipulated to promote the formation of a sample ofbody fluid in the wound.

The needle may be vibrated in any desired and effective motion,including an up and down motion, a side to side motion, a circularmotion, a rotation motion or any combination thereof. This creates amomentary opening in which the blood can fill while the device draws theblood through the needle into the disposable sample collection chamber.The vibration of the needle may occur across a broad range, from 30cycles per minute up to 1000 cycles per minute or more. This slightvibration does not measurably increase the sensation felt by thepatient, particularly when a short duration time is used, but doesmarkedly increase the sample volume which may be easily withdrawn from agiven wound and the rate at which the sample volume is produced from thewound. The oscillation can cause the needle to move up to 2-3 mm percycle. The optimal needle oscillation is less than 1.5 mm, with about0.5 mm preferred based on current investigations. Oscillating orrotating the needle from 30 cycles per minute up to 1000 cycles perminute or more holds the wound open and prevents it from closing andstopping sample collection and provides sample collection in a shorteramount of time.

Lancing conventionally occurs at a 90 degree angle (perpendicular) tothe skin surface. However, we have found that the lancing member maypuncture significantly more capillaries if the lancing is performed on aangle. At a too shallow angle, no significant depth of penetration isachieved. Lancing at an incident angle of 15-90 degrees to the surfaceof the skin is effective, with shallower angles producing greater bloodflow.

The device and system of this invention can further enhance blood flowby massaging the site prior to lancing, as well as by massaging the areaadjacent the lancing cite while the lancing member is in the wound andafter it is removed from the wound, as well as during sample collection,as described above. Alternate methods can use a wiper to rub across orvibrate the skin or can apply heat to the skin to increase the bloodflow to the sampling site.

In another alternate configuration, the lancing needle may be withdrawnvery slightly from the point of maximum penetration to create an openingin which blood can pool before being suctioned through the device. Thiscan be accomplished with a double stop system which stops the needle atmaximum penetration then stops the retraction of the needle at partialbut not full retraction. The area surrounding the wound can be kneadedor massaged by optional movable members mechanical to stimulate bloodflow to the wound and increase the sample size and the rate ofproduction of the sample. The mechanical motion can displace the areaaround the wound from 0.05 to 8 mm, with 1-5 mm being preferred based oncurrent investigations. A wiper device can be used in the aspect whichrubs the skin to increase the blood flow to the wound by stimulating thecapillaries.

The mechanical stimulation of the wound can be accomplished by differentmethods or motions and members. An annular ring or other polygon orblade or paddle members may be oscillated around the wound bypiezoelectric, ultrasonic, solenoid/coil, motor and cam or other methodsapparent to one skilled in the art. Mechanical oscillation in the rangeof 2 to 1000 cycles per minute may be employed, with 10 to 400 cyclesbeing preferred. Ultrasonic vibration has been effective at a frequencyas high as 40 kHz. Alternately, the device may employ a blade orsqueegee type of stimulator which kneads the site with horizontal or acombination of horizontal and vertical action and promotes blood flow tothe wound. The squeegee may act on the wound area 2 to 200 times perminute, with 60 times per minute preferred based on currentinvestigations. Additionally, the needle may be vibrated ultrasonically,with or without the kneading or massaging action adjacent the wound. Theultrasonic vibration can cover the range of ultrasonic frequenciesdepending on the sampling area and whether the needle or the stimulationdevice is being activated.

In another aspect of this invention the lancing member is contained amulti-chambered or multi-channelled capillary disposable member whereinone chamber contains the lancing member and an adjacent chamber isadapted to receive the blood or fluid exiting the wound. Themulti-chambered capillary disposable can be made from any suitablematerial, and installed in the sampler so that it is positioned in theappropriate position relative to the wound created to permit collectionof the sample. The lancing device is driven into the skin and withdrawnby the secondary retraction springs after reaching the limit stops.After withdrawal of the lancing member, the stimulator ring or otherpolygon shape is oscillated by one of the various methods to pump bloodfrom the capillaries adjacent to the wound. The sampling device of thisaspect of the invention has stop mechanisms to limit the penetration ofthe lancing member and sample duration system which sets the time of thesample collection. The lancing guide chamber can be formed a variety ofways and one skilled in the art can reconfigure it to create alternateembodiments.

In another aspect similar to the above, the lancing member can becontained within a single capillary tube and adapted to extend from theend of the tube to create the wound. The lancing member then retracts asufficient distance inside the capillary to allow the desired sample tobe collection in the end of the same capillary tube in the space belowthe retracted lancing member. In such an embodiment the lancing membercan be vibrated in the wound before retraction, also as described above.

To achieve the sample collection after withdrawing the needle, astimulator ring can be used to pump the sample from the surroundingcapillaries through the wound opening. The stimulator ring is designedto keep the skin taut to allow better penetration of the skin duringlancing and help keep the wound open during pumping. It can beoscillated appropriately to insure that enough sample is pumped from thelocal capillaries. The time or number of cycles varies by individual andlocation being sampled. To achieve a variable sample time either of thefollowing methods may be used. A sensor can be built into the samplerwhich senses the blood in the collection chamber or device. When anadequate sample level (which may be adjustable) is reached, thestimulation mechanism is turned off. A second method is to have apatient definable input which sets the time duration for the test or thenumber of cycles for the stimulation ring. Additional stimulator motionscan be employed to promote the extraction of bodily fluids. Theseinclude sinusoidal motion, wobbling, kneading or peristaltic motion. Analternate stimulator device can be designed with an inner and outer ringwhich will alternate creating a peristaltic pumping motion on thecapillaries surrounding the wound. Another alternate stimulator deviceuses a spiral spring that can be compressed flat to emulate multiplepimping rings. As will be apparent, various configurations of multiplestimulator rings, paddles, or other members, used in various rhythms andorders of movement can be employed in the present invention. Thestimulator ring or member can be heated in order to heat the skin toincrease the capillary volume flow to and out of the wound. In addition,the housing or case of the device or other components of the device canbe heated to provide heating of the skin.

In another aspect of the invention a diffused laser may be used topenetrated to the superficial vascular plexus and a capillary tube maybe used to collect the sample. A lens may be used to diffuse the laserso that it does not create a large wound or damage large areas of skinand tissue. A minimum wound size is important to enable rapid healing.The capillary collection tube can use a suction generator to draw thesample up the tube and can also utilize an optional stimulator ring topump the blood from the adjacent capillary beds.

In another aspect of the invention the lancing can be accomplished by apulse of a fluid under high pressure such as a liquid or a compressedgas. In addition the compressed gas can be directed, at lower pressure,to the skin surface to massage the skin before lancing, during lancingand/or during sample collection. Pulsing the compressed gas against theskin at desired pressures, patterns and intervals, including sequentialpattern across the surface of the skin, can provide the desiredstimulation of the blood flow into and from the wound. The pulse ofcompressed gas used to perform the lancing and opening of the wound canbe a single pulse or multiple pulses, can be directed through acapillary sample collection tube, and/or can be applied vertically tothe skin surface or at an angle, as described above for other lancingmembers, to achieve puncturing the maximum capillaries in the skin andprovide the sample collection in a short period of time.

In another aspect of the invention an off meter test device is used witha sampler of this invention to provide an integrated sampling andtesting device. This device can be used by the patient to essentiallysimultaneously draw a sample and test for the presence or concentrationof an analyte in a body fluid. The sample can be taken from an alternatelocation other than the fingertips with the device of this invention. Toaccomplish this it is critical to the test to provide a mechanism tostimulate the wound and or the surrounding area to provide an adequatesample for the test device. This stimulation can be accomplished bymanipulating the needle or the area of skin surrounding the wound asdescribed above. A combination of the two methods can be employed toincrease the volume and/or decrease the sampling time. The sample isintroduced directly into a test device or testing area rather than beingcollected and subsequently dispensed.

In another aspect, this invention also provides a method of determiningthe correct sample size prior to transferring or testing. Differentmethods can be used to sense the volume and/or presence of the sample.One system uses two contacts to sense the presence and/or volume of asample. The body fluid either is drawn up a tube or wells up on thesurface of the skin where it creates a short between two contacts whichsignal that the proper sample has been drawn. An alternate system usesan LED and receiver. When the sample rises to the level where it blocksthe LED from the receiver the proper sample has been drawn. Otheroptically activated or contact activated systems can be used in thisaspect of the invention.

In another aspect, this invention also provides a method of making aunit with a disposable section to limit biohazard cross contamination.

In another aspect, this invention provides a bell shape capillary tube.The capillary tube wicks the sample up the tube until it reaches thetransition of the bulb. The bulb is then depressed to expel the sampleor a known volume of the sample to a desired location, such as a teststrip or device for analysis. The bell shape can be designed as a coneand the sample is wicked up the cone and dispensed by reversing the coneand expelling the sample by capillary action onto the test device.

In an alternate embodiment the device of this invention lances andstimulates the area, creating a drop of sample fluid, which is collectedon or transferred directly to a test device by applying the test deviceto the drop.

In another aspect, this invention can also include an auto-injectiondevice. A preloaded tip may be placed into the barrel. The trigger andspring system can be designed to deliver the sample from the syringerather than to collect a sample into the syringe. One who is skilled inthe art could readily reconfigure the mechanism described to inject asample. Moreover, the device may have dual function of collecting asample while simultaneously or sequentially injecting a sample, whichcan be in response to a test performed in the device on the samplecollected.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a device of this invention having a double stop mechanism.

FIG. 2A and FIG. 2B are cross section views of a device of thisinvention in the cocked and the deployed position, respectively.

FIG. 3 shows a longitudinal cross section of a device according to thisinvention having a stimulator member proximate to the lancet or needle.

FIG. 4 shows the stimulator member positioned on the skin of the patientadjacent the wound and the lance.

FIG. 4A provides a schematic layout of the skin illustrating where thesuperficial vascular plexus capillaries are relative to the skin'ssurface.

FIG. 4B is a representation of a wound, shown in cross section, whichwill facilitate the formation of a small pool of blood yet ensure thatthe skin will fully contract around the wound following sampling topromote healing. The relationship of the wound, needle and thesuperficial vascular plexus capillaries is also illustrated. In theembodiment shown the capillary is offset in the needle.

FIGS. 4C and 4D show alternative embodiments in which, to enhance samplecollection and minimize the wound size required, the needle may bevibrated mechanically in either an up and down motion as shown in FIG.4C or a side to side as shown in FIG. 4D.

FIG. 4E shows that the needle may be vibrated ultrasonically with orwithout the kneading or massaging action.

FIGS. 4F and 4G show that the area surrounding the wound can be kneadedby optional mechanical motion to stimulate blood flow to the wound andincrease the sample size and the rate of production of the sample.

FIG. 4H shows that, alternately, the device may employ a squeegee typeof stimulator which kneads the site with horizontal or a combination ofhorizontal and vertical action and promotes blood flow to the wound.

FIG. 4I shows an alternate embodiment in which needle is oscillated orrotated.

FIGS. 5A and 5B show front and side views of a replaceable needle with aspade tip design adapted for use in this invention, especially for amoving/rotating needle for holding a wound open during samplecollection.

FIGS. 6A and 6B illustrate a front and side view of a disposable needlethat has an eccentric passageway for sample collection. The needle canhave a luer lock type connection to the sample device of this invention.

FIG. 7 shows a needle with a collar or sleeve to provide mechanicalspreading of the wound during sample collection.

FIGS. 8A and 8B are longitudinal cross section views of a device with amulti-chambered capillary members accommodating a lancet or needle inone chamber and providing another chamber or conduit for samplecollection.

FIGS. 8C, 8D and 8E are top view cross section views of two and threechamber capillary members.

FIGS. 9A and 9B illustrate a longitudinal cross section of a devicehaving a multi-chambered capillary disposable and peristaltic pump tocollect a sample.

FIG. 9C illustrates in cross section an alternate suction/standoff/lancedisposable tip containing contacts for electrically sensing the presenceand/or volume of body fluid.

FIG. 10 illustrates in cross section a device with a laser positioned toradiate through the interior of the needle or capillary for piercing theskin.

FIG. 11 illustrates in longitudinal cross section in cross section adevice of this invention for use with a combined suction/standoffchamber as part of a disposable sample collection system.

FIGS. 12A and 12B illustrate a longitudinal cross section and side viewcross section of a device of this invention having and angled lancet orneedle and employing an absorbent strip.

FIGS. 13 and 14 show a longitudinal cross section and a side view crosssection of a sampling device of the present invention with an integratedcolorimetric instrument test.

FIG. 15 shows a longitudinal cross section of an sampling device of thepresent invention with an integrated electrochemical test.

FIGS. 16 and 17 show a longitudinal cross section and a side view crosssection of a sampling device of the present invention with an integratedcolorimetric visual test.

FIG. 18 shows an alternate device which has a completely disposablelower section to minimize blood contamination between uses.

FIG. 19A shows the combination of a dual alternating stimulation ringsystem.

FIG. 19B shows the device with a telescoping stimulator ring.

FIGS. 20A, 20B and 20C illustrate a bell shape capillary tube and FIG.20D shows a straight capillary tube with a test strip.

FIG. 21 illustrates a device of this invention with a member tooscillate the needle to stimulate fluid flow from the wound.

FIG. 22A shows a multiple needle lancing device.

FIG. 22B shows a broader single lancet.

FIGS. 22C and 22D show a die cut sheet which has small multiple barbsformed in the sheet for use as a lance in the present invention.

DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a minimally invasive sampling device according to theinvention. The device is comprised of numerous components which will bemore fully described below. The main body 1 supports the variousmechanical components housed within the device.

The main body 1 comprises an elongated hollow cylindrical tube withopenings at both ends. The sampling needle 16 which is part of thedisposable 3 which is capable of being retracted or deployed so that itcan protrude beyond the needle guard 17 is positioned at one end. Thearming and dispensing plunger 22 protrudes from the other end. Thedevice has a needle guard 17 which permits the loading of the disposable3. Disposable 3 is attached to the syringe 13 and plunger 14 is releasedby the suction cam 8.

The syringe 13 is captivated to the drive system by syringe clamp 12which has the main tie rods 4 anchored to it. The main drive springs 11are captivated between the syringe clamp 12 and cross support 10 and thetie rods 4 are threaded through them.

The main tie rods 4 have the main cams 9 attached to them and aresupported by the activation trigger 2 prior to release. The secondarysprings 21 and secondary stops 20 provide a mechanism after activationto pull the needle back out of the wound to permit blood accumulation.When the skin is pierced the secondary springs 20 retract the needlefrom the wound triggering the suction cam 8 and plunger 14 is released.The arming and dispensing plunger 22 is a dual purpose device. When thepatient pulls up, it preloads the drive springs 11. It is latched bypushing in on the activation trigger 2.

The stop and adjustment tabs 19 control the depth of penetration of theneedle 16 so that the optimal depth of penetration is reached for aparticular sample site. The sample 15 is drawn from the patient when thedevice has been deployed by releasing the activation trigger 2 and theneedle 16 has been retracted from the patient.

The system shown in FIGS. 2A and 2B is comprised of a reusable barrel 1and associated mechanisms and a sterile disposable 13. The disposable 13has an ultra fine gauge needle 16 which is imbedded in a cap until thedevice is readied for use. FIG. 2B shows the device in the deployedstate with a sample in disposable 13 and FIG. 2A shows it undeployed.

Main yoke 3 is held by activation triggers 2 which support the main tierods 4 when the system is undeployed. The system is activated byreleasing the activation triggers 2. This releases the main cam 9 whichcauses the syringe to be deployed by the drive spring 11 which iscaptured between the cross support 10 and the syringe clamps 12. Theneedle 16 pierces the skin as a result of these actions and thepenetration depth is controlled by stop 27. When the suction cams 8 isreleased by the secondary trigger 5, the suction spring 6 is released.This drives the suction yoke 7 up slowly due to the damping action ofthe syringe plunger 14 so a back pressure or vacuum is created in thesyringe body. Sample 15 is actively drawn into the syringe.

The sample can be delivered easily and precisely to a test device orother container by pressing down on a button on the top of the sampler.The disposable syringe 13 and needle 16 may be imbedded in the cap inwhich it was shipped or placed into a Sharps container for safedisposal.

To insure that adequate sample size is collected the needle 16 can bevibrated, oscillated or rotated to keep the wound from closing. Thedisclosure of FIGS. 3, 4, 4C, 4D, 4E, 4I, 9, 12 and 13 show and describevarious alternative motions that can be used to accomplish this.

Another version of this device is also capable of performing as anauto-injection device. A preloaded tip may be placed into the barrel.The trigger and spring system can be designed to deliver the sample fromthe syringe rather than to collect a sample. One who is skilled in theart could readily reconfigure the mechanism described to inject asample.

FIG. 3 illustrates a minimally invasive sampling device according to theinvention. The device is comprised of numerous components which will bemore fully described below. The main body 1 supports the variousmechanical components housed within the device.

The main body 1 comprises an elongated hollow cylindrical tube withopenings at both ends. The sampling needle 16 which is part of thedisposable 3 which is capable of being retracted or deployed so that itcan protrude beyond the needle guard 17 is positioned at one end. Thearming and dispensing plunger 22 protrudes from the other end. Thedevice has a needle guard 17 which can be slid up and down main body 1by the patient to permit the loading of the disposable 3. Disposable 3is attached to the syringe 13 by the tip adapter 18. The internal partsof the syringe 13 are the plunger 14 which is activated by the suctionspring 6 and the suction yoke 7. The plunger is released when thesuction cam 8 is released by the secondary trigger 5.

The syringe 13 is captivated to the drive system by syringe clamp 12which has the main tie rods 4 anchored to it. The main drive springs 11are captivated between the syringe clamp 12 and cross support 10 and thetie rods are threaded through them.

The main tie rods 4 have the main cams 9 attached to them and aresupported by the activation trigger 2A prior to release. The secondarysprings and secondary stops 20 provide a mechanism after activation topull the needle back out of the wound to permit blood accumulation. Whenthe skin is pierced the secondary springs retract the needle from thewound and initiate the stimulation ring 25 oscillation system 26 and 27to force blood flow to the wound. The arming and dispensing plunger 22is a dual purpose device. When the patient pulls up, it preloads thedrive springs 11. It is latched by pushing in on the activation trigger2A.

The stop and adjustment tabs 19 control the depth of penetration of theneedle 16 so that the optimal depth of penetration is reached for aparticular sample site. The stimulator ring can be deployed duringlancing to keep the skin taut, thus allowing more accurate andrepeatable penetration of the skin. The sample 15 is drawn from thepatient when the device has been deployed by releasing the activationtrigger 2 and the needle 16 has retracted from the patient.

FIG. 4 illustrates the relationship of the needle 16, wound 200 andstimulation ring 25. The detail areas of the skin are shown for clarity.The stimulator ring 25 is used to pump the sample of body fluid 61 intowound area 200. A singular stimulation ring 25 is shown in thisillustration. However, multiple telescoping rings may be employed toenhance the blood transport.

The stimulation ring can also be formed to with a series of notches topermit the resupply of body fluid to the capillaries when thestimulation ring 25 is retracted from the wound site 200.

In an alternate embodiments the stimulation ring is heated or asecondary motion added to act as a wiper to enhance the flow of bodyfluid to the wound 200. Other members can be used instead of a ring toprovide the stimulation desired.

FIGS. 4C, 4D and 4E illustrate that the needle may be vibrated in thedesired motion. This creates a momentary opening in which the blood canfill while the device draws the blood through the needle into thedisposable sample collection chamber. The vibration of the needle mayoccur across a broad range, from 30 cycles per minute up to 1000 cyclesper minute or more. This slight vibration does not measurably increasethe sensation felt by the patient but does markedly increase the samplevolume which may be easily withdrawn from a given wound and the rate atwhich the sample volume is produced from the wound. The oscillation cancause the needle to move up to 2-3 mm per cycle. The optimal needleoscillation is less than 1.5 mm, with about 0.5 mm preferred based oncurrent investigations. Lancing generally occurs at a 90 degree angle(perpendicular) to the skin surface. However, the lancing member maypuncture significantly more capillaries if the lancing is performed on aangle. At a very shallow angle, no significant depth of penetration isachieved. Lancing at an incident angle of 15-90 degrees to the surfaceof the skin is effective, with shallower angles producing greater bloodflow. The ultrasonic vibration can cover the range of ultrasonicfrequency depending on the sampling area and whether the needle or thestimulation device is being activated.

FIGS. 4F and 4G show massaging or kneading the area surrounding thewound. The mechanical motion can displace the area around the wound from0.05 to 8 mm, with 1-5 mm being preferred based on currentinvestigations. FIG. 4G shows a wiper device which rubs the skin toincrease the blood flow to the wound by stimulating the capillaries.This action can also be done by the patient by rubbing the area toincrease the blood flow to the sampling site prior to taking a sample.The oscillation can be accomplished via piezoelectric, ultrasonic, or byusing a solenoid/coil or a motor and cam. Mechanical oscillation in therange of 2 to 1000 cycles per minute may be employed, with 20 to 200cycles being preferred. Ultrasonic vibration has been effective at afrequency as high as 40 kHz. FIG. 4F shows an alternate embodiment inwhich the wound is mechanically stimulated such as by an annular ringwhich may be oscillated.

FIG. 4H shows massaging with a squeegee type of stimulator. Such asqueegee may act on the wound area 2 to 200 times per minute, with 60times per minute being preferred.

FIG. 4I shows rotating or oscillating the needle from 30 cycles perminute up to 1000 cycles per minute or more. This holds the wound openand prevents it from closing and stopping sample collection. Thisembodiment can employ the needles disclosed herein in FIGS. 4B, 5A, 5B,6A and 6B, conventional needles or round or flat lancets.

FIGS. 5A and 5B show a spade tip needle/lance profile which is used bythe invention to create a void area in the wound. FIGS. 5A and 5B showone needle profile which is useful in implementing this embodiment. Thespade end helps create a void area when it is rotated in the smallwound.

FIGS. 6A and 6B show an asymmetric needle design to create a wound whichcan enhance capillary blood collection. Needle 16 is molded to formdisposable 3. Another aspect of the invention is the provision of aneasily replaceable lancing tip (FIGS. 6A and 6B). The tip must attach tothe device simply to facilitate the availability of a fresh, sterileneedle for each sample drawn. A wide range of lancet or needle gaugesmay be used for the tip. Current investigations show that 10 through 32gauge is acceptable depending on the sampling location. The entiredevice may also be designed as a single use device. In thisconfiguration, the device would be precocked and would only trigger anddispense once. A new device with a sterile tip would be thus used foreach sample drawn. It will be apparent that an alternate disposable canbe constructed from a needle and flexible tube. The tube acts as areservoir for the sample as it is drawn by the applied vacuum. Anothercapillary type disposable is shown in FIG. 31. The bell type disposableuses capillary action to wick the sample up the tube until it reachesthe bulb or vacuum created by depressing the bulb. The sample isdispensed by collapsing the bulb. Anyone skilled in the art would beable to readily reconfigure the design presented herein to be a singleuse device.

FIG. 7 illustrates the use of a needle 16 with a flexible collar 225 andstimulator ring 25 to hold the wound open during the extraction of thebody fluid sample. The collar 225 is affixed to the needle and acts as astop and as a means of spreading the wound. This provides a means offorcing the wound open during sampling. The collar 225 can be fashionedin various configurations to achieve the same results by one skilled inthe art.

FIG. 8A shows the lancing member is part of a multi-chambered capillarydisposable. FIG. 8B provides an exploded view of the end of the deviceshowing the relation ship of lancet 30, disposable 33 and lancet guidetube 35. The multi-chambered capillary disposable can be made from anysuitable material. FIGS. 8C, 8D and 8E show various, alternatives ofthis embodiment. One skilled in the art could readily reconfigure adisposable which would be equal to this invention.

The lancet 30 creates the wound and is guided by guide tube 35. Thesample is drawn up the sample collection tube/disposable 33. Thecomplete device can either be fashioned as one single disposable ormultiple components.

FIG. 9A illustrates a minimally invasive sampling device according tothe invention using the alternate capillary disposable blood collectiondevice FIG. 8A which is disposable 33. The device is comprised ofnumerous components which will be more fully described below. The mainbody 1 supports the various mechanical components housed within thedevice. FIG. 9B shows the cutout to allow communication of blood to thesample collection tube.

The main body 1 comprises of an elongated hollow cylindrical tube withopenings at both ends. The capillary sampling disposable with lancingmember 30, which is part of disposable 33 and is capable of beingretracted or deployed so that it can protrude beyond the end of the mainbody 1, is positioned at one end. The arming plunger assembly 36protrudes from the other end. The lancing member 30 is guarded by beingwithdrawn into the needle guide tube 35 which is part of the disposable33. The needle guide tube 35 acts as the lancing guide and lancet guard.The disposable 33 is attached to the main body 1 so that it ispositioned at the appropriate location to guide the lancet and suctionup the blood. The striker 39 is projected so as to drive the lancet intothe patient 41 by the spring 43 and the arming plunger assembly 36. Thearming plunger is locked in place by a cam 45 and trigger 47. A doublestop return spring 49 is located and sized to return the lancet 30 backinto the disposable 33 needle guide tube 35. The needle guard 17supports the main body 1 on patient 41.

The double stop return springs 49 provide a mechanism after activationto pull the needle back out of the wound to permit blood 61accumulation. When the skin is pierced the secondary springs 49 retractthe needle from the wound and initiate the stimulation ring 25oscillation system to force blood flow to the wound. The stimulator ringcan oscillate in the preferred range of 1 to 5 mm. The frequency canvary from 5 to 1000 cycles per minute in the preferred embodiment. Theoscillation of the stimulator ring 25 is driven by the coils 51 whichoscillate the stimulator ring 25 to pump the blood 61 from thesurrounding capillaries in the skin into the wound. Each down stroke ofthe stimulator ring 25 provides this pumping action. This pumping actioncan be modified to include sinusoidal motion, wobbling, kneading orperistaltic motion which will enhance the blood flood to the wound.

A linkage 53 drives a peristaltic roller system 55 and rollers 57against the suction tube 59 causing blood 61 to be drawn up the suctiontube 59 creating the sample 15.

The stop and adjustment tabs 19 control the depth of penetration of thelancet 30 so that the optimal depth of penetration is reached for aparticular sample site.

In another aspect of this invention, electric potential can be appliedacross the skin to also stimulate blood flow to the wound. This can beaccomplished by having separate electrodes present in the device tocontact the skin and deliver the electric current at locations desired.Or, the current can be delivered to the skin through components of thedevice, appropriately insulated internally of course, such as thestimulator ring 25 and sample tube 59, or any other appropriatecombination. In general, low voltage DC or AC current can aid in bloodflow. The voltage, amperage and cycles (in the case of AC) can bedetermined by one skilled in the art, but DC voltage in the range of 1millivolt to 12 volts will be useful. Likewise, the duration of theapplied current or the pulsing thereof can be selected as desired. In aparticular example tube 33 in FIG. 9A or needle 16 in FIG. 3 can be thenegative electrode and ring 25 in FIG. 9A and FIG. 3 or guard 17 can bethe positive electrode.

FIG. 9C illustrates a alternate suction/stand off chamber bloodcollection device 72 which comprises of lance 30, suction tube 59,secondary tube which guides the lance 30, suction/standoff chamber 105,and contacts 107 and 109. The suction tube 59 is mounted insuction/standoff chamber 105 so as to permit the suction tube to belocated off the wound to promote bleeding while the wound is stimulated.The contacts provide a means of determining if the sample size isadequate. Contacts 109 are made when adequate volume of blood is presentin the cap 105 and these are in communication with contacts 107 whichare in communication with the electronic package of the sampler. Oncecontacts 109 are made by the blood then the circuit is completedsignaling the system to stop.

FIG. 10 illustrates a minimally invasive sampling device according tothe invention using the alternate capillary disposable blood collectiondevice and laser 67 lancing mechanism. The device is comprised ofnumerous components which will be more fully described below. The mainbody 1 supports the various mechanical components housed within thedevice.

The main body 1 is comprised of an elongated hollow cylindrical tubewith openings at both ends. The capillary sampling disposable withdiffusing lens member 60 which is part of disposable 63 is installed inone end of the main body 1. The firing switch 65 protrudes from theother end. The capillary tube 59 acts as the laser guide and samplecollection device. The disposable 33 is attached to the main body 1 sothat it is positioned at the appropriate location to direct the laserand to suction up the blood. The laser 67 is diffused by going throughthe lens and creates the wound in the patient.

When the skin is pierced, the laser shuts down. This initiates thestimulation ring 25 oscillation system to force blood flow to the wound.The oscillation of the stimulator ring 25 is driven by the coils 51which oscillate the stimulator ring 25 so as to pump the blood 61 fromthe surrounding capillaries in the skin into the wound. Each down strokeof the stimulator ring 25 provides this pumping action. A linkage 53drives a peristaltic roller system 55 and rollers 57 against the suctiontube 59 causing blood 61 to be drawn up the suction tube 59 creating thesample 15. The oscillation of the stimulator ring can have a range of 0to 8 mm and preferably 1 to 5 mm. The frequency can also vary from 2 to100 cycles per minute.

In an alternative embodiment for the device of FIG. 10, the lancingmeans can be a liquid under high pressure or a compressed gas pulseinstead of the laser. A pulse of compressed gas, or multiple pulses, canbe directed at the skin. In addition, the liquid under pressure orcompressed gas pulses can be applied in the annular space between ring25 and housing 1 to massage and stimulate the skin to increase bloodflow to the wound.

It is to be understood that the vacuum employed in the variousembodiments of this invention can be used with the capillary tubes, suchas 59 in FIG. 10, as well as the needles of FIGS. 4B, 5A and B, and 6Aand B.

FIG. 11 illustrates a minimally invasive sampling device according tothe invention using the alternate suction/stand off chamber bloodcollection device 72 which is more fully described in illustration 9C.The device is comprised of numerous components which will be more fullydescribed below. The main body is 1 which supports the variousmechanical components housed within the device.

The main body 1 comprises of an elongated hollow cylindrical tube withopenings at both ends. The suction/stand off chamber sampling disposablewith lancing member 30 which is part of disposable 72 and is capable ofbeing retracted or deployed so that it can protrude beyond the end ofthe main body 1 positioned at one end. The arming tabs/trigger 37protrude from the sides of main body 1. The disposable 72 is attached tothe main body 1 so that it is positioned at the appropriate location toguide the lancet and suction up the blood. The striker 39 is projectedso as to drive the lancet into the patient 41 by the spring 43 and thearming plunger assembly 37. The arming plunger is locked in place by acam 45 and trigger 37. A double stop return spring 49 is located andsized to return the lancet 30.

In another aspect, the capillary sample collection tubes used in thevarious embodiments of this invention, such as 33 in FIGS. 8A and 9A, 59in FIGS. 9C and 10 and 150 in FIGS. 20A-20C, can be selected to have anaffinity for the sample fluid greater than the skin so the fluid orblood will wick into the tube by capillary action. However, thecapillary tube is also selected to have less affinity for the samplefluid or blood than a test strip or test device surface of receivingport so that the sample fluid or blood will wick out of the capillarytube into or onto the test strip or device. Such materials for thecapillary tube can easily be determined and selected by one skilled inthe art, but generally capillary tubes of nylon, PTFE, and the likegenerally fulfill this function. It will be recognized that theselection of such material for the capillary tube must be made relativeto materials present in and the physical construction the test strip ordevice, if this aspect of the present invention is to be utilized.

The double stop return springs 49 provide a mechanism after activationto pull the needle back out of the wound to permit blood 61accumulation. When the skin is pierced, the secondary springs 49 retractthe needle from the wound and initiate the stimulation ring 25oscillation system to force blood flow from the wound. The stimulatorring can oscillate in the preferred range of 1 to 5 mm. The frequencycan vary from 5 to 1000 cycles per minute in the preferred embodiment.The oscillation of the stimulator ring 25 is driven by the motor 51which oscillate the stimulator ring 25 to pump the blood 61 in thesurrounding skin capillaries from the wound so the blood can flow to thesurface of the skin, bead up, and contact the disposable 72. Each downstroke of the stimulator ring 25 provides this pumping action. Thedisposable 72 is then lowered onto the blood bead using a secondarymotion spring 74 that is released by a secondary motion trigger 75, andsuction of the blood initiated. The suction device 85 shown here is amini syringe which is activated by spring 86 when secondary motiontrigger 75 is released causing blood 61 to be drawn up the disposable72. The stop and adjustment cap 19 controls the depth of penetration ofthe lancet 30 so that the optimal depth of penetration is reached for aparticular sample site.

FIGS. 12A and 12B illustrate a minimally invasive sampling deviceaccording to the invention using a disposable piercing apparatus, areusable sampling device and a disposable absorbent test strip 83. FIG.12A shows the device in a side view and FIG. 12B is a front view. Thedevice is comprised of numerous components which will be more fullydescribed below. The main body is 1 which supports the variousmechanical components housed within the device.

The main body 1 comprises of an elongated hollow cylindrical tube withopenings at both ends. The lancing member 30 which is part of disposable33 is capable of being retracted or deployed so that it can protrudebeyond the end of the main body 1 is positioned at one end. The armingtabs 37 protrude from the sides of main body 1. The lancing member 30 isguarded by being withdrawn into the tube 35 which is part of thedisposable 33. The tube 35 acts as the lancing guide and lancet guard.The disposable 33 is attached to the main body 1 so that it ispositioned at the appropriate location to guide the lancet and is heldin place by the disposable clamp 3. The striker 39 is projected so as todrive the lancet into the patient 41 by the spring 43 and the armingplunger assembly 36. The arming plunger is locked in place by a cam 45and trigger 47. A double stop return spring 49 is located and sized toreturn the lancet 30 back into the tube 35.

The double stop return springs 49 provide a mechanism after activationto pull the needle back out of the wound to permit blood 61accumulation. When the skin is pierced the secondary springs 49 retractthe needle from the wound and initiate the stimulation ring 25oscillation system to force blood flow to the wound. The cam 55oscillates the oscillator ring 57 which transmits the motion tostimulation ring 25. The stimulator ring can oscillate in the preferredrange of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles perminute in the preferred embodiment. The oscillation of the stimulatorring 25 is driven by the motor 51. The battery 56 provides energy to runthe motor 51 which oscillates the stimulator ring 25 to pump the blood61 from the surrounding capillaries in the skin into the wound. Eachdown stroke of the stimulator ring 25 compresses the stimulator spring53 which provides the return motion for the stimulator ring 25. Thedisposable chemical strip 83 is then lowered onto the blood bead using asecondary motion spring 74 that is released by a secondary motiontrigger 75. The blood is absorbed by the disposable chemical strip 83which fits into a slot in the main body 1 and the stimulator ring 25.

The stop and adjustment tabs 19 control the depth of penetration of thelancet 30 so that the optimal depth of penetration is reached for aparticular sample site.

FIGS. 13 and 14 illustrate an integration of the minimally invasivesampling device with a chemical test measurement, such as glucose, andelectronic readout according to the invention using a disposablepiercing apparatus 33, a reusable sampling device 1, a disposableabsorbent test strip 83, and a method of readout such as colorimetrictest which is read electronically and has an electronic readout system.FIG. 13 shows the device in a side view and FIG. 14 is a front view. Thedevice is comprised of numerous components which will be more fullydescribed below. The main body is 1 which supports the variousmechanical and electrical components housed within the device.

The main body 1 comprises of an elongated hollow cylindrical tube withopenings at both ends. The lancing member 30 which is part of disposable33 is capable of being retracted or deployed so that it can protrudebeyond the end of the main body 1 is positioned at one end. The armingtabs 37 protrude from the sides of main body 1. The lancing member 30.is guarded by being withdrawn into the tube 35 which is part of thedisposable 33. The tube 35 acts as the lancing guide and lancet guard.The disposable 33 is attached to the main body 1 so that it ispositioned at the appropriate location to guide the lancet and is heldin place by the disposable clamp 3. The striker 39 is projected so as todrive the lancet into the patient 41 by the spring 43 and the armingplunger assembly 36. The arming plunger is locked in place by a cam 45and trigger 47. A double stop return spring 49 is located and sized toreturn the lancet 30 back into the tube 35.

The double stop return springs 49 provide a mechanism after activationto pull the needle back out of the wound to permit blood 61accumulation. When the skin is pierced the secondary springs 49 retractthe needle from the wound and initiate the stimulation ring 25oscillation system to force blood flow to the wound. The cam 55oscillates the oscillator ring 57 which transmits the motion tostimulation ring 25. The stimulator ring can oscillate in the preferredrange of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles perminute in the preferred embodiment. The oscillation of the stimulatorring 25 is driven by the motor 51. The battery 56 provides energy to runthe motor 51 which oscillates the stimulator ring 25 to pump the blood61 from the surrounding capillaries in the skin into the wound. Eachdown stroke of the stimulator ring 25 compresses the stimulator spring53 which provides the return motion for the stimulator ring 25. Thedisposable chemical strip 83 is then lowered onto the blood bead using asecondary motion spring 74 that is released by a secondary motiontrigger 75, and suction of the blood initiated. The blood is absorbed bythe disposable chemical strip 83 which has been manufactured into thedisposable 33. The strip is then read in place by a LED 88 colorimetricsystem and analyzed by electronics which are part of the device anddisplayed on display 84.

The stop and adjustment tabs 19 control the depth of penetration of thelancet 30 so that the optimal depth of penetration is reached for aparticular sample site.

FIG. 15 illustrates an integration of the minimally invasive samplingdevice with a chemical test measurement, such as glucose, and electronicreadout according to the invention using a disposable piercing apparatus33, a reusable sampling device 1, a disposable absorbent test strip 83,and a method of readout such as a electrochemical test which is readelectronically and has an electronic readout system. The device iscomprised of numerous components which will be more fully describedbelow. The main body is 1 which supports the various mechanical andelectrical components housed within the device.

The main body 1 comprises of an elongated hollow cylindrical tube withopenings at both ends. The lancing member 30 which is part of disposable33 is capable of being retracted or deployed so that it can protrudebeyond the end of the main body 1 is positioned at one end. The armingtabs 37 protrude from the sides of main body 1. The lancing member 30 isguarded by being withdrawn into the tube 35 which is part of thedisposable 33. The tube 35 acts as the lancing guide and lancet guard.The disposable 33 is attached to the main body 1 so that it ispositioned at the appropriate location to guide the lancet and is heldin place by the disposable clamp 3. The striker 39 is projected so as todrive the lancet into the patient 41 by the spring 43 and the armingplunger assembly 36. The arming plunger is locked in place by a cam 45and trigger 47. A double stop return spring 49 is located and sized toreturn the lancet 30 back into the tube 35.

The double stop return springs 49 provide a mechanism after activationto pull the needle back out of the wound to permit blood 61accumulation. When the skin is pierced the secondary springs 49 retractthe needle from the wound and initiate the stimulation ring 25oscillation system to force blood flow to the wound. The cam 55oscillates the oscillator ring 57 which transmits the motion tostimulation ring 25. The stimulator ring can oscillate in the preferredrange of 1 to 5 mm. The frequency can vary from 5 to 1000 cycles perminute in the preferred embodiment. The oscillation of the stimulatorring 25 is driven by the motor 51. The battery 56 provides energy to runthe motor 51 which oscillates the stimulator ring 25 to pump the blood61 from the surrounding capillaries in the skin into the wound. Eachdown stroke of the stimulator ring 25 compresses the stimulator spring53 which provides the return motion for the stimulator ring 25. Thedisposable test strip 83 is then lowered onto the blood bead using asecondary motion spring 74 that is released by a secondary motiontrigger 75, and suction of the blood initiated. The blood is absorbed bythe disposable chemical strip 83 which has been manufactured into thedisposable 33. The strip is then read in place by a milliamp/ormillivolt sensing electronics depending on the specific chemistry of thetest strip. This reading is converted into a chemical concentration bythe onboard electronics and displayed on the LCD on the side of thedevice.

The stop and adjustment tabs 19 Control the depth of penetration of thelancet 30 so that the optimal depth of penetration is reached for aparticular sample site.

FIGS. 16 and 17 illustrate an integration of the minimally invasivesampling device with a chemical test measurement, such as for glucose,using a disposable piercing apparatus 33, a reusable sampling device 1,a disposable absorbent test strip 83 capable of providingsemiquantitative colorimetric results. The device is comprised ofnumerous components which will be more fully described below. The mainbody is 1 which supports the various mechanical and electricalcomponents housed within the device.

The main body 1 comprises of an elongated hollow cylindrical tube withopenings at both ends. The lancing member 30 which is part of disposable33 is capable of being retracted or deployed so that it can protrudebeyond the end of the main body 1 is positioned at one end. The armingtabs 37 protrude from the sides of main body 1. The lancing member 30 isguarded by being withdrawn into the tube 35 which is part of thedisposable 33. The tube 35 acts as the lancing guide and lancet guard.The disposable 33 is attached to the main body 1 so that it ispositioned at the appropriate location to guide the lancet and is heldin place by the disposable clamp 3. The striker 39 is projected so as todrive the lancet into the patient 41 by the spring 43 and the armingplunger assembly 36. The arming plunger is locked in place by a cam 45and trigger 47. A double stop return spring 49 is located and sized toreturn the lancet 30 back into the tube 35.

The double stop return springs 49 provide a mechanism after activationto pull the needle back out of the wound to permit blood 61accumulation. When the skin is pierced the secondary springs 49 retractthe needle from the wound and initiate the stimulation ring 25oscillation system to force blood flow to the wound. The cam 55oscillates the oscillator ring 57 which transmits the motion tostimulation ring 25. The stimulator ring can oscillate in the preferredrange of 1 to 5 mm. The frequency can vary from 20 to 200 cycles perminute in the preferred embodiment. The oscillation of the stimulatorring 25 is driven by the motor 51. The battery 56 provides energy to runthe motor 51 which oscillates the stimulator ring 25 to pump the blood61 from the surrounding capillaries in the skin into the wound. Eachdown stroke of the stimulator ring 25 compresses the stimulator spring53 which provides the return motion for the stimulator ring 25. Thedisposable chemical strip 83 is then lowered onto the blood bead using asecondary motion spring 74 that is released by a secondary motiontrigger 75, and suction of the blood initiated. The blood is absorbed bythe disposable chemical strip 83. The strip is then removed and read bythe patient.

The stop and adjustment tabs 19 control the depth of penetration of thelancet 30 so that the optimal depth of penetration is reached for aparticular sample site.

FIG. 18 illustrates an integration of the minimally invasive samplingdevice using a disposable piercing, stimulating and puncture depthadjustment apparatus 92. The device can assume any of the configurationsdescribed by this invention. This modification replaces items 19, 30,72, 25, 3 on a typical reusable sampling device such as FIG. 11. Thedisposable unit can incorporate a test strip, a sample container, anelectrical sensing unit, or other testing or sampling component.

FIG. 19A shows the concept of a dual alternating stimulation ringsystem. The secondary stimulation ring 120 alternates it's position 180degrees out of phase of stimulation ring 25. This creates a peristalticpumping action on the capillaries adjacent to the wound. This device canbe used with any embodiment to increase the blood flow. Link 121connects the two rings with body 1. The peristaltic pumping results insqueezing the body fluid to the wound by massaging the fluid inwardtowards the wound.

FIG. 19B shows the concept of concentric collapsing stimulation ring. Inthis embodiment the inner ring 25 contacts the skin after the outer ring120. Spring 299 provides resistance and sequencing so that the outerring 120 contacts the skin prior to inner ring 25. This squeezes thebody fluid to the wound by massaging the fluid inward towards the wound.

In an alternate embodiment ring 25 can also function as the samplecollection tube after lancing needle 16 is retracted.

In another alternate embodiment compressed gas pulses can be applied inthe annular spaces between housing 1 and ring 120 and/or between ring120 and ring 25 to massage the skin and stimulate blood flow. Suchaction by compressed gas pulses can be used instead of or in combinationwith the movement of ring 120 or other stimulation members.

FIG. 20A illustrates a bell shape capillary tube 150 which is used tocapture a sample of body fluid. The bell shape capillary is shaped tofit around the drop and it is drawn up the tube until it reaches thebulb 151. This assist in assuring that adequate sample 152 is drawn andthe bulb 151 breaks the capillary action. The sample 152 is dispensed bycompressing the bulb 151. The capillary can be heated to increase thedraw of the capillary tube and the speed of the sample collection.

FIGS. 20B and 20C show an alternative method where the sample 152 iswicked up the tube 150 and the tube is inverted so that the sample canby transferred to a absorbent test pad 153.

FIG. 20D shows a strait capillary 310 where the sample 152 is wicked upthe tube 310 and is transferred to the absorbent test pad 153 bycapillary action of the pad.

The tubes shown in 20A, 20B, 20C, and 20D can be modified with asurfactant to increase the ability to wick up the bodily fluid.

FIG. 21 illustrates a device where the oscillation ring 130 is fixturedto disposable clamp 3 to oscillate the needle 33 to stimulate the woundand hold it open so that it does not close around the wound. In additiona heated ring 135 can be used to increase the capillary volume tostimulate blood flow.

FIG. 22A shows a multiple needle lancing device which is used to causemultiple wounds to increase sample size. The multiple needles are ofsufficient size and length to minimize the pain sensation and stillgenerate adequate sample size.

FIG. 22B shows a broader single lancet which is used to cause multiplewounds to increase sample size.

FIGS. 22C and 22D shows a die cut sheet which has small. multiple barbsformed in it which is used to cause multiple wounds to increase samplesize. The multiple barbs are of sufficient size and length to minimizethe pain sensation and still generate adequate sample size.

The lancing device of FIGS. 22A through 22D can be used in the samplingdevices disclosed herein.

1. An apparatus for obtaining a sample of body fluid, comprising: a skinpiercing member; and a drive mechanism connected to the skin piercingmember; wherein the drive mechanism is adapted to extend the skinpiercing member to a point of maximum penetration beneath a skin surfaceand withdraw the skin piercing member from the point of maximumpenetration while maintaining the skin piercing member beneath the skinsurface to create an opening in which body fluid can pool.
 2. Theapparatus of claim 1, further comprising: a double stop system, whereina first stop defines the point of maximum penetration and a second stopdefines the point where the skin piercing member creates the opening inwhich body fluid can pool.
 3. The apparatus of claim 1, wherein the skinpiercing member includes a fluid passage, the apparatus furthercomprising: a suction mechanism adapted to create suction to draw bodyfluid through the fluid passage.
 4. The apparatus of claim 1, furthercomprising: a sample collection chamber connected to the drivemechanism, wherein the drive mechanism is reusable and the samplecollection chamber is disposable.
 5. The apparatus of claim 1, whereinthe skin piercing member is disposable and the drive mechanism isreusable.
 6. The apparatus of claim 1, wherein the point of maximumpenetration is at a depth of 0.3 to 0.6 millimeters below the skinsurface.
 7. The apparatus of claim 1, further comprising: a penetrationdepth adjustment mechanism adapted to adjust the depth to which the skinpiercing member penetrates beneath the skin surface.
 8. The apparatus ofclaim 1, further comprising: a needle guard connected to the drivemechanism, the needle guard adapted to contact the skin surface andinhibit the skin piercing member from contacting the skin while the skinpiercing member is in a retracted position.
 9. A method, comprising:extending a skin piercing member of a fluid sampling device to a pointof maximum penetration beneath a skin surface with a drive mechanism;and withdrawing the skin piercing member from the point of maximumpenetration with the drive mechanism while maintaining the skin piercingmember beneath the skin surface and forming an opening between the skinpiercing member and the skin in which body fluid can pool.
 10. Themethod of claim 9, further comprising: moving fluid from the openingbetween the skin piercing member and the skin through a passage in theskin piercing member.
 11. The method of claim 9, further comprising:forming a vacuum; and drawing fluid from the opening between the skinpiercing member and the skin using the vacuum.
 12. The method of claim9, further comprising: moving fluid from the opening between the skinpiercing member and the skin to a sample collection chamber connected tothe drive mechanism.
 13. The method of claim 9, wherein said extendingresults in the skin piercing member reaching a maximum depth of 0.3 to0.6 millimeters below the skin surface.
 14. The method of claim 9,further comprising: limiting the point of maximum penetration beneaththe skin surface to a value that can be adjusted.
 15. The method ofclaim 9, wherein said extending includes extending the skin piercingmember beyond a needle guard, the needle guard being adapted to contactthe skin surface.
 16. An apparatus, comprising: a reusable fluidsampling device including a drive mechanism; and a disposable memberdetachably mounted to the drive mechanism and adapted to be replacedafter use, the disposable member including a skin piercing member with afluid passageway, the skin piercing member being adapted to penetrate askin surface; wherein the drive mechanism extends the skin piercingmember to a point of maximum penetration beneath the skin surface and,while maintaining the skin piercing member in the wound, pulls the skinpiercing member back to permit body fluid accumulation; and wherein thefluid passageway is adapted to draw fluid from the accumulated bodyfluid.
 17. The apparatus of claim 17, wherein the point of maximumpenetration is at a depth of 0.3 to 0.6 millimeters below the skinsurface.
 18. The apparatus of claim 17, wherein the reusable fluidsampling device includes a suction mechanism in communication with thefluid passageway, the suction mechanism adapted to draw accumulated bodyfluid through the fluid passageway.
 19. The apparatus of claim 19,wherein the suction mechanism includes a syringe with a plunger.
 20. Theapparatus of claim 19, further comprising: a penetration depthadjustment mechanism adapted to adjust the depth to which the skinpiercing member penetrates beneath the skin surface.